Author: Pacific NW Fertility Team
One of the most common questions I answer as a fertility doctor is, ‘Should I exercise or not while trying to conceive?’ It can be confusing as a patient trying to navigate the conflicting advice from the internet, friends, and family. Women are told everything from ‘Absolutely no exercise while trying to conceive!’ to ‘Exercising is great, BUT not during a certain time in the cycle’ to ‘It’s okay to exercise, BUT not too much and not this type.’ Women are left confused and often terrified of doing the wrong thing, and they may stop exercising completely losing a healthy way of maintaining fitness and decreasing anxiety – and a source of joy.
I ask my patients what type of exercise they are currently doing and walk through ways to maintain or modify their routines for their personal situation. Every patient is unique, but everyone should keep their body moving in ways that are right for them. Instead of broad, general, and dogmatic rules, let’s review the literature and some unique situations to help answer the question: ‘To exercise or not to exercise while trying to conceive.’
Exercise is good for you. Study after study shows the benefits of regular exercise as a means of preventing chronic illnesses like cardiovascular disease, type 2 diabetes, breast and colon cancers, and more (1). Lack of exercise is often related to obesity, and many studies find that obesity is directly linked to reproductive issues such as menstrual irregularities, ovulation dysfunction, and higher risk of poor obstetric outcomes (2). Exercise is important in all women, regardless of weight; interesting research shows lower fertility rates in women with normal weight with a sedentary lifestyle (3). However, studies in athletes with high levels of vigorous exercise show a negative impact on menstrual cycles, ovulation, and fertility, leading researchers to conclude that too much exercise is not good for fertility (4). So if you re-read these last few sentences, you can see how confusing the data on exercise for women trying to conceive can be – exercise is ‘good’ for health and fertility in women who are obese or normal weight, BUT women shouldn’t exercise too much, because that’s ‘bad’ for fertility. What should women do?
Exercise While Trying to Conceive
Although there are many studies on exercise and fertility, they all differ in the patients they study, the questions they are trying to answer, and the approach they take to try to answer those questions. Some find exercise improves fertility, and some warn that too much exercise can lead to infertility.
An excellent meta-analysis (a paper designed to compile data from different studies) published in 2019 (5) helped review the data critically and draw together recommendations to help answer the fitness and fertility question. The authors concluded that physical activity (alone or in combination with diet) has beneficial effects on reproductive outcomes and that pregnancy rates can be twice as high in patients maintaining regular exercise compared to no exercise while trying to conceive. The benefits are most helpful in patients with obesity, polycystic ovarian syndrome, and insulin resistance, and moderate physical activity did not significantly improve or harm success with fertility treatment. The authors, while recognizing the many limitations of clinical research, support the general conclusion that exercise is good for women trying to conceive and in fertility treatment – unfortunately, they did not provide specific answers on how much exercise or how intense the exercise should be.
Polycystic ovarian syndrome (PCOS) is a collection of signs and symptoms such as irregular menstrual cycles, high levels of male hormones resulting in acne and excessive hair growth or loss, insulin resistance, difficulty losing weight, and infertility. The diagnosis of PCOS is not black and white, and many patients exhibit some but not all signs and symptoms. The relationship between physical activity, obesity, and insulin resistance associated with PCOS has been studied extensively, and one review of five studies showed improved ovulation, weight loss, and insulin resistance with moderate exercise for 12- to 24-week exercise programs (6). Patients with PCOS who are ready to conceive can be frustrated by irregular menstrual cycles – it’s difficult to time ovulation and intercourse, and months can go by just trying to figure out whether or not ovulation is occurring. Options for these patients include ovulation induction with medication, but some evidence shows that regular physical activity (with or without weight loss) improves hormonal profiles, regulates menstrual cycles, and is associated with higher chances of ovulation and conception in some PCOS patients (6). Exercise with weight loss in obese PCOS patients is beneficial, and exercise with or without weight loss is beneficial for all PCOS patients.
Higher body mass index (BMI) and weight are associated with infertility, irregular menstrual cycles, and a higher risk of poor obstetric outcomes like miscarriage (2), and many studies researching the impact of exercise on fertility focus on obese patients. Not surprisingly, improved outcomes with weight loss are shown in many studies (5) and are especially beneficial for obese patients with PCOS (7). Interestingly, some studies show improved cycle regularity, ovulation, and even live births were not necessarily associated with weight reduction but were improved in obese women changing diet and increasing exercise while trying to conceive (5). One study showed that natural conceptions can improve with physical activity in obese patients whether or not the number on the bathroom scale changes (8). I find this data encouraging for patients who are frustrated with efforts to lose weight while trying to conceive. When counseling patients, I focus on the goal of being healthy – not an arbitrary weight goal. Losing weight will likely eventually happen with consistent healthy lifestyle and physical fitness, but benefits like improved insulin resistance, hormonal balance, and improved mood can happen immediately with regular exercise!
If patients should maintain healthy exercise while trying to conceive – then what about during their IVF cycle? In vitro fertilization (IVF) requires a woman giving herself gonadotropin medication in the form of daily shots to stimulate her ovaries to recruit multiple eggs to mature in a menstrual cycle. There are many different protocols for IVF, but a typical cycle involves preparation before the cycle in the form of two to three weeks of birth control pills, two weeks of daily shots, an egg retrieval, an embryo transfer three to five days after the egg retrieval if a fresh embryo transfer or a period of seven to ten days after the egg retrieval if the patient is freezing all the eggs (egg cryopreservation/egg freezing) or embryos (eggs fertilized with sperm). The medications, multiple appointments, and recovery from the egg retrieval procedure can take a toll on our already busy lives, and many women describe bloating and fatigue during the process. Women may not feel like exercising during the cycle but maintaining low impact movement can improve mood and sleep – and speed up recovery.
Many women are told not to exercise at all during their IVF cycle, and this warning comes from the rare but real risk of ovarian torsion during IVF stimulation and recovery. The ovaries are suspended by ligaments on both sides, attached to the pelvic side wall on one end and the uterus on the other. Torsion is a process in which the ovary twists on itself, with the blood supply running through these ligaments getting cut off in the twisting process. One risk for ovarian torsion is IVF, when the ovaries are enlarged with developing follicles (the fluid-filled structures surrounding maturing eggs), but ovarian torsion is rare, occurring in 0.03% of IVF cycles (10). Ovarian torsion is a medical emergency and can require surgery to untwist the ovary to allow for blood circulation. Women with torsion describe ‘the worst pain of their lives’ associated with nausea or vomiting, usually sudden onset in the setting of a moving or twisting motion. It sounds dramatic, and it is (like testicular torsion), and I’m describing it in detail because women can have aches and pains during IVF stimulation, and I do not want women worried that those aches are torsion (review concerns with your doctor).
The general guideline for ‘no exercise’ in IVF is from the worry that patients may be at an increased risk of ovarian torsion while exercising with enlarged ovaries. Some recommendations for exercise during IVF to consider:
No high impact exercise with quick changes in body position.
Walking or light jogging, but no quick twisting.
Swimming, but no flip turns at the end of the lane.
Yoga, but no inversions.
No vigorous acrobatics (I’ve had patients who ask about trapeze and circus exercise during IVF – Nope!).
Talk to your doctor about advice for you, but consider walking, light jogging (but not near the time of retrieval), lifting light weights, and gentle yoga without significant twisting or inversions. Keep moving but modify your normal routine.
My patients often ask about altering activity in pregnancy, and many are worried about doing anything to jeopardize the health of a pregnancy they have worked so hard to achieve. There are some health conditions like cervical incompetence, placenta previa, risk of preterm labor, and heart and lung disease in the mother where doctors will ask patients to limit exercise. However, the American Society of Obstetrics and Gynecology encourages moderate aerobic and strength conditioning exercises in uncomplicated pregnancies (11). Regular physical activity in pregnancy improves or maintains physical fitness, reduces excessive weight gain in pregnancy, decreases the risk of gestational diabetes, and enhances emotional well-being.
Common exercise in pregnancy guidelines I’ve heard and read include:
1) Continue the same amount and type of exercise routine in pregnancy as established before pregnancy. Pregnancy is not the right time to train for a marathon for the first time or join a new cross-fit class, but maintaining or slightly decreasing the intensity of a routine you’ve established is most likely okay for you (check with your doctor).
2) Work out, but watch your heart rate and keep it under (140 or 160 beats per minute). This guideline comes from the theoretical risk of decreasing blood supply to the uterus and pelvis with intense exercise. This is a tough guideline to give to patients, because some intense athletes never get a high heart rate with exercise. An arbitrary number can confuse many patients.
So, talk to your doctor about your personal situation, but in general, with uncomplicated pregnancies – keep moving! Be patient with yourself if your body doesn’t feel the same as pre-pregnancy and if your endurance is diminished. Remember, early pregnancy can lead to fatigue, nausea, and other symptoms that make exercise less appealing. Try to keep moving a little each day or a few times a week, but be kind to yourself and your body.
What about men’s exercise and fertility? This is an important question to ask, and we know that high heat can negatively impact sperm parameters (think hot tubs), but how can we counsel men about biking, jogging, and hot yoga? Studies on exercise and men’s fertility differ in many ways – who they study, how they determine fertility (sperm parameters vs. time to conception), and how they study (questionnaire vs. interview). Most of the studies available warn against strenuous, intense endurance exercise like running and biking for long periods of time but find improved sperm counts and fertility with regular exercise. One study found decreased sperm counts with more than five hours of biking per week in men undergoing fertility testing (12). A study of sperm parameters in sedentary men monitored during exercise programs showed improved counts and motility in sperm with regular cardiovascular exercise and a return to poor parameters when exercise stopped (13). So exercise is good for men’s fertility too!
One warning about fitness and men’s fertility: testosterone and steroid supplements often used to enhance fitness performance will decrease sperm counts and often lead to infertility. It may seem counterintuitive, and patients often question me when I tell them this because it seems like testosterone would improve sperm like it improves muscle mass and athletic performance, BUT it’s true! If the body sees exogenous testosterone and steroids (in the form of shots, creams, pills), it stops making its own testosterone – and if testicles aren’t making testosterone, they stop making sperm too. There are clinical trials underway looking into the use of testosterone as a male contraception! So – do not take testosterone, and be very careful about herbs and supplements aimed to ‘boost men’s muscle mass and athletic performance,’ because they may contain steroids or testosterone-like compounds.
Exercise is good for you; however, you may want to modify your routine while trying to conceive and in early pregnancy. Please review your personal situation with your doctor to find a routine that is right for you, but here are some general thoughts I share with most patients:
1) Keep moving when trying to conceive, because regular, moderate exercise improves overall health, success with treatment, and sperm parameters – and it decreases time to pregnancy in many couples.
2) Excessive exercise can be counterproductive. Pushing your body to exhaustion and getting to a negative energy state (too few calories and excessive exercise) can increase cortisol and stress hormones and decrease gonadotropin hormones, leading to irregular menses, ovulation dysfunction, and poor sperm parameters. It’s tough to counsel patients who love their hard work outs on this, but I’ll talk about exercising less than one hour a day, maintaining the ability to talk through workouts, and not pushing to a point of endorphin release (aka runner’s high).
3) Find a routine or group of exercises you can do through the cycle and in pregnancy. Some women will alter their exercise based on their menstrual cycles – they’ll push to exhaustion and train before ovulation and then become sedentary after ovulation until their pregnancy test. This adds to the emotional roller coaster ride of trying to conceive, and I advise against it.
4) Regular aerobic exercise with or without weight loss in patients is beneficial. Do not make weight loss the only goal for an exercise routine, because there are many benefits – including improved mood, sleep, cardiovascular health, and reproductive health!
5) Modify your routine in an IVF cycle to decrease the risk of ovarian torsion (see IVF section).
6) An achievable goal can be moderate exercise 30 minutes a day, three to four times a week. You don’t have to join a gym or spend a significant amount of money to get moving. Try walking, light jogging, yoga, Pilates, biking (less than five hours a week for men), or weight training. Get a fitness app on your phone that can guide you through exercises in your living room.
Review your routine with your doctor, get moving, and enjoy!